ERBB2 and neoplasm: To overcome the drug resistance problem of trastuzumab, GSK developed an oral and dual TKI lapatinib (Tykerb), a 4-aniline quinazoline small molecule compound (C29H26ClFN4O4S, 581.06), which simultaneously targets HER1 and HER2 to block their downstream signaling pathways and inhibit tumor growth by blocking the binding of ATP to kinases.